B2/6th Bandpass Chassis
Printed From: Speakerplans.com
Category: Plans
Forum Name: Other plans
Forum Description: Discussion / Questions about all the other plans
URL: https://forum.speakerplans.com/forum_posts.asp?TID=27958
Printed Date: 26 March 2026 at 10:12pm
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: B2/6th Bandpass Chassis
Posted By: airbell
Subject: B2/6th Bandpass Chassis
Date Posted: 18 June 2009 at 10:29pm
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Hello I have two B2 Subs, or I guess its not the original, just from paplans.de.vu, and a lot of people says this are not the original sizes inside.. but however they work very well outside with a load of deep bass They're built as 6th bandpass enclosures (3 chambers)! Loaded with RCFL18S800.. Just want to know if there're some chassis that work better in that sub than the l18s800.... Do they need a big vas, or isn't it much important a high BL? a lower or a higher qts, and xmas as big as possible? the p audio sd 18 has JUST 5mm linear cone excursion...! would the b&c 18sw 115 fit into it? with more power and more max spl output? * 96dB * Fs 35 Hz * Re 5.3 ohm * Qes 0.37 * Qms 6.3 * Qts 0.35 * Vas 145 dm3 (5.10 ft3) * Sd 1210 cm2 (187.60 in2) * ?0 1.6 % * Xmax ± 14 mm * Xvar ± 15 mm * Mms 300 g * Bl 30.6 Txm * Le 1.9 mH Or is there any better? |
Replies:
Posted By: airbell
Date Posted: 18 June 2009 at 10:34pm
sry forgot the tsp from the l18s800 700w rms rs 39hz 99.5dB vas 206l Qts 0,29 Bl 24.5 xmax 6,8mm and the b&c driver has 1700w rms/aes... |
Posted By: Ibex
Date Posted: 29 June 2009 at 9:46pm
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Hi airbell, I read somewhere in this forum that d&b first used the RCF L18S800, then they changed to the B&C 18PZB46 (which is replaced by the B&C 18PZB100). They are supposed to be OEM versions with slightly heavier cones... In the following plots you can see the differences between the driver evolution. They are bloody similar. The B&C 18SW115 won't be the best choice, you had to accept a bumpier frequency response... I don't know, if it would sound as good as with the other alternative drivers, because I think a flat response isn't the most crucial...  black = d&b B2 x2 - B&C 18PZB46 grey = d&b B2 x2 - RCF L18S800  black = d&b B2 x2 - B&C 18PZB100 grey = d&b B2 x2 - RCF L18S800  black = d&b B2 x2 - B&C 18SW115 grey = d&b B2 x2 - RCF L18S800 greez |
Posted By: airbell
Date Posted: 15 July 2009 at 1:21am
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Thanks for your graphs Ibex Just wondered why you used Hornresp to simulate this, because thought B2 isn't a "really" horn at all, more a BP..(?) Anyway, the RCF18S800 has a more flat frequence response I agree and a higher average spl rated on 1W/1m. But as i simulated a "half" B2 with WinISD I could see by full rated power that the cone excursion is over max at around 50hz!! That's the same what I'm asking me about the x1 sub from Rog...the Paudio SD 18 he suggested has only 5mm max cone excoursion. that's so low for a bandpass sub that should move a lot of air...(??) And Rog himself wrote the SD multiplicated with the max linear cone excursion is the factor how much air the driver is able to move and so how much max bass is able to produce! and that was my philosophy by naming the 18sw115 because the chassi has about 1700w rms and a xmax=+14mm/-14mm!! of course probably you need a lot of power but the max spl should be a lot greater..or am i wrong?? please correct me im not sooo much experienced... |
Posted By: Ibex
Date Posted: 15 July 2009 at 10:34am
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No problem, airbell! You have to know, that it is possible to simulate every enclosure type as an horn
 Furthermore the B2 middle chamber is ported via a small horn. But you are right, it is a 6th order bandpass design.
Note, that the voice coil/cone is able to move out of the linear excursion range as well, but in this case the driver will produce more distortion.
For sure, the more cone movement the more max SPL you can expect.
cheers
ps: eigentlich könnten wir in deutsch fachsimpeln, allerdings würde, sofern sich jemand in diesem forum für diesen thread interessiert, niemand etwas verstehen...?
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Posted By: audionik
Date Posted: 29 October 2009 at 8:57pm
| Did you ever compare L18s800 to LW 1400 in B2 or other sub? |
Posted By: MarjanM
Date Posted: 29 October 2009 at 11:02pm
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Ibex can you post screen shot of the input data i am too interested in how to simulate some of my drivers in that box. Tnx ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: Ibex
Date Posted: 01 November 2009 at 11:22am
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Posted By: Ibex
Date Posted: 01 November 2009 at 11:34am
 black = d&b B2 x2 - 18Sound 18LW1400 grey = d&b B2 x2 - RCF L18S800 |
audionik wrote:Posted By: audionik
Date Posted: 02 November 2009 at 7:55pm
And do you have the graph of 18TBX100 vs LW1400 or L18p300? Have you the same for RCF L18S8001? Thanks. |
Posted By: Ibex
Date Posted: 02 November 2009 at 8:04pm
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Most are bloody similar... here you are: http://s682.photobucket.com/albums/vv181/Ibex2912/B2%20vs%20X1/ (note that the sims are for 2 cabs, with a single cab arrangement the second peak dominates the bottom end peak) greez |
Posted By: bitzo
Date Posted: 02 November 2009 at 8:06pm
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too kind Ibex, you give input data and some example other users can sim by theirself.
------------- http://www.unitedroots.it - United Roots SoundSystem site |
Posted By: Ibex
Date Posted: 02 November 2009 at 8:11pm
| input available on the link above... |
Posted By: audionik
Date Posted: 02 November 2009 at 8:58pm
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Hi, I have not hornresp, so please have you the sim between LW1400 and RCF L18P300? Thanks. |
Posted By: bitzo
Date Posted: 02 November 2009 at 9:15pm
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download it, it's freeware, google is your friend and D. McBean too . ------------- http://www.unitedroots.it - United Roots SoundSystem site |
Posted By: Ibex
Date Posted: 02 November 2009 at 9:20pm
| bitzo, don't be so accommodating, lenient towars him, he's only since april this your sp member... |
Posted By: BMJ Sound
Date Posted: 18 March 2011 at 6:19pm
I have a pair of 18 sound lw1400 in single super scoops powered by crown xls5000 amplifier and would not like to be around 4 or 8 of these bins because they are ridiculously loud but do maintains quality i build the scoops myself i have to check the db at the horn mouth non the less 18 sound lw1400 18 inch... ------------- Cracking the atmosphere with bass |